From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 2BB396B004D for ; Mon, 29 Jun 2009 17:14:00 -0400 (EDT) MIME-Version: 1.0 Message-ID: <6639b922-4ed7-48fd-9a3d-c78a4f93355c@default> Date: Mon, 29 Jun 2009 14:13:56 -0700 (PDT) From: Dan Magenheimer Subject: RE: [RFC] transcendent memory for Linux In-Reply-To: <20090629203619.GA6611@elf.ucw.cz> Content-Type: text/plain; charset=Windows-1252 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Pavel Machek Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, npiggin@suse.de, chris.mason@oracle.com, kurt.hackel@oracle.com, dave.mccracken@oracle.com, Avi Kivity , jeremy@goop.org, Rik van Riel , alan@lxorguk.ukuu.org.uk, Rusty Russell , Martin Schwidefsky , akpm@osdl.org, Marcelo Tosatti , Balbir Singh , tmem-devel@oss.oracle.com, sunil.mushran@oracle.com, linux-mm@kvack.org, Himanshu Raj List-ID: > > It is documented currently at: > >=20 > > http://oss.oracle.com/projects/tmem/documentation/api/ > >=20 > > (just noticed I still haven't posted version 0.0.2 which > > has a few minor changes). > >=20 > > I will add a briefer description of this API in Documentation/ >=20 > Please do. OK, will do. > At least TMEM_NEW_POOL() looks quite ugly. Why uuid? Mixing flags into > size argument is strange. The uuid is only used for shared pools. If two different "tmem clients" (guests) agree on a 128-bit "shared secret", they can share a tmem pool. For ocfs2, the 128-bit uuid in the on-disk superblock is used for this purpose to implement shared precache. (Pages evicted by one cluster node can be used by another cluster node that co-resides on the same physical system.) The (page)size argument is always fixed (at PAGE_SIZE) for any given kernel. The underlying implementation can be capable of supporting multiple pagesizes. So for the basic precache and preswap uses, "new pool" has a very simple interface. > > It is in-kernel only because some of the operations have > > a parameter that is a physical page frame number. >=20 > In-kernel API is probably better described as function prototypes. Good idea. I will do that. Thanks, Dan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org